Business transactions between parties are usually formalized by signing documents that specify the terms of the agreement between the parties. The nature of the business transaction can determine the number and complexity of the documents.
In the context of real estate transactions, for example, there can be multiple different forms, signed at different times by buyers, sellers, real estate agents, and escrow agents, among others. When a seller places their home on the market for sale, the seller often signs a listing agreement with a real estate agent. When an interested buyer makes an offer on the home, the buyer can condition the offer upon a number of contingencies, such as a home inspection, the sale of the buyer's current home, and other contingencies, that become part of the offer. The seller may make counteroffers. This process may go back and forth until an agreement is reached. At that point, the agreed upon price and all of the conditions are signed by the parties and a binding contract is formed. Most of the time the parties are not in the same physical location when the offers, counteroffers, and acceptances are signed. Fax machines are often used to facilitate the process, as well as emailing scanned documents.